zuercher



March 31, 1964 E. A. ZUERCHER, JR 3,126,714

AUTOMATIC ICE MAKER Filed May 10, 1962 2 Sheets-Sheet 1 F 'Ie, .28

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F'IGZ INVENTOR. EDWARD A ZUERCHER JR BY Z/MWL l-HS ATTORNEY Mam}! 1964E. A. ZUERCHER, JR 3,126,714

AUTOMATIC ICE MAKER Filed May 10, 1962 2 Sheets-Sheet 2 INVENTOR. EDWARDA. ZUERCHER 3R H(S ATTORNEY United States Patent 3,125,714 AUTGMATIQ IQEMAKER Edward A. Zuercher, Ira, Fern Creek, Ky, assignor to GeneralElectric Company, a corporation of New Yorl: Filed May 11" 1962, Ser.No. 193,746 3% (Ilaiins. (Cl. 62137) The present invention relates to anautomatic ice maker and is particularly concerned with a compact icemaker adapted to be incorporated in a domestic or householdrefrigerator.

An object of the present invention is to provide a new and improveddomestic or household refrigerator ice maker including a mold or traycontaining a plurality of cavities from which ice pieces are released bycentrifugal forces resulting from rotation of the mold about a verticalaxis.

Another object of the present invention is to provide an automatic icemaker including a mold and means for rotating the mold for centrifugaldischarge of ice pieces therefrom and centrifugally operated controlmeans for stopping the operation of the ice maker when the requiredquantity of ice has been manufactured.

A further object of the invention is to provide an automatic ice makerincluding means for centrifugally discharging ice pieces from an icemold and control means for initiating the ice harvesting cycle inresponse to a subfreezing temperature of the ice mold and forterminating the harvesting cycle as soon as the ice pieces have beencentrifugally removed from the mold.

Additional objects and advantages of the invention will become apparentas the following description proceeds and the features of novelty whichcharacterize the invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

In carrying out the objects of the present invention, there is providedan ice mold including a plurality of cavities or pockets from which icepieces formed therein can be centrifugally discharged by rotation of themold about a vertical axis. The ice mold is preferably of annular shapeand comprises a plurality of radially extending pie-shaped cavitiesincluding radially extending side walls and sloping end Walls adjacentthe periphery of the mold whereby rotation of the mold about its centeror axis will cause the ice pieces formed in the mold cavities to becentrifugally discharged therefrom. To facilitate the release of the icepieces, the mold is preferably composed not only of a plastic materialsuch as polystyrene, polyethylene or the like having a low adhesion forice but is also SllffiClGl'lilY resilient or flexible so that flexing ordistortional vibrations will be set up in the mold during rotation tofacilitate the breaking of the ice bond with the cavity surfaces.

For the purpose of stopping the operation of the ice maker when therequired quantity of ice has been collected in a storage receptacleassociated with the ice maker, there is also provided a centrifugallyoperated level sensing means operated by the same drive means employedto rotate the mold during the ice harvesting cycle and adapted to becentrifugally raised from its sensing position during each harvestingcycle and to stop operation of the ice maker in the event it does notreturn to its sensing position when rotation of the mold is stopped Inits preferred form, the ice maker also includes control circuitry forinitiating the harvesting cycle, that is rotation of the ice mold, whenthe mold attains a predetermined sub-freezing temperature and to stopthe rotation :as soon as the ice pieces have been centrifugallydischarged from the mold.

For a better understanding of the invention, reference may be had to theaccompanying drawings in which:

FIGURE 1 is a front elevational view of the freezer compartment of ahousehold refrigerator having positioned therein the ice maker of thepresent invention;

FIGURE 2 is a view taken generally along line 2-2 of FIGURE 1;

FIGURE 3 is a sectional view of the ice maker taken generally along line3-3 of FIGURE 2; and

FIGURE 4 is a wiring diagram for an electric control system employed forthe automatic control of the ice maker of the present invention.

As illustrated in FIGURE 1 of the drawing, the ice maker of the presentinvention indicated by the numeral 1 is designed to be positioned in thefreezing chamber 2 of a household refrigerator which is refrigerated byair circulated by means of a fan 3 over an evaporator 4. Preferably theice maker is positioned immediately in front of an outlet 5 for the airwhich has been circulated over and cooled to sub-freezing temperaturesby the evaporator. Also positioned within the freezer compartment 2immediately below the ice maker is a receptacle or bin 6 in which icepieces discharged from the ice maker are stored in an ambienttemperature below freezing.

With reference particularly to FIGURE 3 of the drawing the ice makercomprises a support 7 secured by any suitable means to one side wall 8of the compartment 2 and the support '7 includes a base 9 on which amotor 10 including a drive shaft 11 is vertically mounted. An annularice mold 312 is mounted on the upper end of the shaft 11 in such amanner that it will rotate with the shaft upon operation of the motor16) but is also free to move vertically on the shaft within limitingpositions. In the illustrated embodiment of the invention the drivingconnection between the shaft -11 and the mold 12 com prises a drive dog14 mounted on the shaft and a drive boss 15 secured to the hub portionof the ice mold 12. By this arrangement, the pins 16 forming part of thedog 14 slidably extend into cylindrical recesses 17 in the drive boss toprovide a rotational driving force to the mold 12 upon rotation of theshaft 11. The drive boss 15 forming the hub of the rotatable ice mold isloosely fitted on the shaft 11 so that the ice mold 12 is free to movevertically between an upper position in which the central portion of themold d2 contacts a stop 18 carried by the shaft 11 and a lower positionin which the lower surface Zll of the drive boss rests on the drive dog14. A spring 21 is provided for biasing the ice mold to its upperposition and is of the strength such that the ice mold will be held inits upper position when empty but will move to its ower position whenfilled with water or ice.

The ice mold 12 as illustrated also in FIGURE 2 of the drawing includesa plurality of ice pockets or cavities 22 which are generally pie-shapedor in other words are each defined by radially extending opposed sidewalls 23 and 24 and a sloping outer or peripheral wall 25. By thisconfiguration or any similar configuration in which the outer orperipheral dimensions of the individual cavities 22 are the larger andthe side walls 23 and 24 converge towards the axis 27 of the mold, icepieces formed therein can be discharged from the cavities by centrifugalforces resulting from rotation of the mold about its axis 27. For thepurpose of allowing a charge of water to flow from cavity to cavity,notches 26 are provided in the outer ends of the side walls.

Preferably the mold 122 is composed of a resilient or somewhat flexibleplastic material such as polystyrene, polyethylene or the like. By theuse of molds of this type, the centrifugal forces on the ice piecesduring rotation of the mold cause the ice pieces to break loose from themold and fly out of the mold. The release and discharge action isaccelerated by any unbalance in the mold which causes distortion orvibration thereof during rotation. If desired an unbalance can bedeliberately built into the mold as for example by arranging to havediametrically opposite portions of the mold somewhat heavier than theremaining portions to force distortion of the resilient material uponrotation thereof. Normally however it has been found that the smallamount of unbalance present in the usual mold as manufactured issufficient to cause quick release of the ice pieces during rotation.

For the purpose of periodically supplying a charge of water to the mold,there is provided a water supply means including an outlet 27 positionedabove the mold 12 and a solenoid operated water valve (shownschematically in FIGURE 4) which may be disposed in the high temperaturecompartment 28 of the refrigerator or in the insulated space between theinner and outer walls of the refrigerator.

Upon rotation of the mold 12 about its vertical axis as represented bythe shaft 11, ice pieces are centrifugally discharged from the mold andfor the purpose of confining these ice pieces to the neighborhood of themold and for directing their discharge into the receptacle 6 positionedbelow the mold, the mold is surrounded by a housing 30 including anannular side wall most of which is positioned close enough to the outeredge of the mold 12 as represented by the mold strengthening skirt 32 sothat the ice pieces cannot fall between these portions of the wall 31and the mold. At one point about the periphery of the mold, a housingside wall portion 33 is spaced a sufiicient distance from the edge 32 ofthe mold so that ice pieces released from the mold can drop through theopening 34 formed by the side wall portion 33 and fall into thereceptacle 6. In order that cold air from the evaporator will circulateabout the contents of the mold 12, air passages 29 are provided in thehousing wall'31.

When the receptacle 6 becomes filled with ice pieces indicated bynumeral 35 so that it is desirable to stop the automatic operation ofthe ice maker, there is provided an ice level sensing means operative toperform its sensing function during rotation of the shaft 11. Thissensing means 37 is mounted on the lower end of the shaft 11 andcomprises a cup-shaped member 38 having a substantially hemisphericalshape and including a hub 39 slidably mounted on the shaft 11 andsecured thereto by a centrifugal mechanism including opposed pairs ofpivoted levers 40 connected at one end to the hub 39 and at the otherend to an arm 41 secured to the shaft 11. By this arrangement, the cupmember 38 is free to move between a lowered or normal position and araised position during rotation of the shaft, movement to the raisedposition being effected by the centrifugal forces on the pivot levers40. Whenever the motor is energized for discharge of ice pieces byrotation of the mold 12, the cup member 38 will be lifted during theperiod that the ice pieces are being discharged in the receptacle 6.When the motor 10 is de-energized the cup is free to drop to its lowerposition unless prevented from doing so by the accumulation of icepieces in the receptacle 6.

For the purpose of controlling the automatic operation of the ice makerthrough the filling and ice harvesting cycles and for stopping theoperation of the ice maker when-sufficient ice is collected in thereceptacle 6, there is provided electrical control circuitry including amold operated switch 43 for controlling the operation of the solenoidvalve 44 and an ice limit switch 45 designed to stop the operation ofthe ice maker when suflicient ice is accumulated in the receptacle 6.

The switch 43 is positioned below the ice mold 12 and includes a switcharm 46 adapted to be engaged by an annular flange 47 when the tray 12 isin its lower or filled position. The normally closed ice limit switch 45is designed to be opened when the sensing member 38 -member 38 is in itselevated position.

is in its raised position and this is accomplished in the illustratedembodiment of the invention by means of cam surfaces 49 provided on theupper end of the pivot levers 40 which are designed to raise the switchmember 50 and open the switch contacts 51 and 52 Whenever the Normallythe switch member 50 is biased downwardly so that the contacts 51 and 52are closed and biased closed by means of a spring 53 carried on theshaft 11 above the member 50.

For energizing the motor 10 upon the freezing of a charge of water inthe mold 12, there is provided a thermostat switch 54 also supported onthe housing 7. While any suitable thermostatic switch may be used, thereis illustrated the usual bulb and bellows type including a sensing bulbor tube 55 positioned closely adjacent the bottom walls of the cavities22. In this position the sensing bulb or tube 55 is protected orshielded from the circulating cold air passing through air passages 29and the upper portion of the housing 30 above the mold 12 by the moldand also by the upwardly extending walls 5'6 provided as part of thesupport 7. When the switch 54 senses a below freezing temperatureindicating that the water contained in the mold has frozen, the controlcircuitry is designed to energize the motor 10 and initiate the iceharvesting cycle.

For a more detailed understanding of the control circuitry and themanner in which it automatically controls the operation of the icemaker, reference is made to FIG- URE 4 of the drawing. As illustrated,the mold operated switch 43 is a double pole switch movable to a firstposition when the mold is empty and to a second position when the moldis full while the thermostat switch 54 is also a double pole switchmovable either to a warm or to cold position as determined by thetemperature adjacent the bottom of the ice mold 12. The controlcircuitry includes a first circuit across the supply lines 57, 58comprising the switch 43 in its empty position, the solenoid valve 44,the centrifugal ice limit switch 45 and the thermostat switch in itswarm position for controlling the energization of the solenoid valve 44.A second circuit for energizing the motor 10 comprises the mold switch43 in its full position, the motor 10 and the thermostatic switch in itscold position.

Assuming that a charge of water has just been introduced into the icecavities 22, the thermostat 54' will sense the warm temperature of thewater in the mold and the thermostat switch will therefore be in itswarm position and as the motor 10 is not energized, the centrifugal icelimit switch 45 will be closed. The mold switch however will be in itsfull position so that the first circuit including the solenoid valve 44will be open. Sub-freezing air circulated through the housing 30 and incontact with the contents of the mold 12 will gradually cause the Watercontained therein to freeze. When the freezing is complete so that thesensing bulb or tube 55 senses a sub-freezing temperature, thethermostat switch 54 will move to its. cold position and, as the moldswitch is in its full position, motor 10 will be energized. Rotation ofthe mold 12 centrifugally discharges the ice pieces from the mold fordischarge through the opening 34 into the receptacle 6. As soon as the.ice pieces have been discharged, the mold will be raised by spring 21 tomove switch 43 to its empty position. During rotation of the mold thecentrifugal switch 45 will be opened and in the event the iceaccumulated in the receptacle 6 is suificient to prevent the feeler cupmember 38 from returning to its lower position, this switch 45 will bemaintained in its open position thereby preventing subsequentenergization of the solenoid valve to introduce another charge of Watereven though the mold switch is in its empty position. In the event thatthe amount of ice in the receptacle 6 is insufficient to prevent cupmember from dropping and again closing switch 45 as soon as the icepieces have been discharged from the mold 12,

switches 4-3 and 45 will both be conditioned to energize the solenoidvalve upon movement of the thermostat switch to its warm position. Thisoperation of the thermostat switch 54 following a harvesting cycle maytake place due to the heat of the motor which is adjacent the sensingbulb 55 or it can be accelerated by providing a heater 59 in heatingposition relative to bulb 55' connected across the lines 57, 53 wheneverthe thermostat switch is in its cold position. The heater 59 is designedto accelerate the warming of the sensing bulb 55 which will cause thethermostat switch to move to its warm position. Upon movement of theswitch 54 to its warm position, the solenoid valve or first circuit isenergized and the valve will remain open to discharge water into themold until the mold switch moves to its full position. Thereafter, withthe tray switch in its full position, the motor circuit will again beenergized whenever the thermostat switch moves to its cold position as aresult of freezing of the water in the mold cavities 22. The ice makeris then conditioned for the next harvesting cycle.

While there has been shown and described a particular embodiment of thepresent invention, it will be obvi us to those skilled in the art thatvarious changes and modi Acations may be made therein without departingfrom the invention and it is intended by the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An automatic ice maker comprising a support;

a drive means including a motor and a vertical drive shaft mounted onsaid support,

an annular ice mold having a plurality of cavities from which ice piecesformed therein will be centrifugally discharged upon rotation of saidtray about a vertical axis,

means for supporting said mold on said shaft for rotation therewith andfor limited vertical sliding movement of said mold on said shaft betweenan upper position when empty and a lower position when filled withWater,

an ice receptacle positioned below said ice tray,

sensing means for sensing the level of ice in said receptacle, saidsensing means comprising a feeler member and centrifugal mechanismsecuring said feeler member to the lower end of said shaft for rotationthereof with said shaft,

said centrifugal mechanism being adapted to raise said feeler memberfrom a normal lower position to a raised position during rotation ofsaid shaft,

water supply means including a solenoid valve,

a thermal switch movable to a cold position in response to a freezingtemperature of said ice mold and a warm position in response to anelevated temperature of said mold,

a mold operated switch movable to a first position when said mold isfilled and a second position when said mold is empty,

a normally closed ice level switch adapted to be opened when said feelermember is in its raised position,

a solenoid valve control circuit comprising said mold operated switch inits first position, said ice level switch and said thermal switch in itswarm position for opening said valve when said mold is empty and at anelevated temperature,

a motor circuit including said mold operated switch in its secondposition and said thermal switch in its cold position for energizingsaid motor when said mold is filled and at a freezing temperature.

2. An automatic ice maker comprising a support;

a drive means including a motor and a vertical drive shaft mounted onsaid support;

an annular ice mold having a plurality of radially extending cavitiesfrom which the ice pieces formed therein will be centrifugallydischarged upon rotation of said tray about a vertical axis,

means for supporting said mold on said shaft for rotation therewith andfor limited vertical sliding movement of said mold on said shaft betweenan upper position when empty and a lower position when filled withwater,

an ice receptacle pos 'oned below said ice tray,

sensing means for sensing the level of ice in said receptacle, saidsensing means comprising a cup-shaped feeier member and centrifugalmechanism securing said feeler member to the lower end of said shaft forrotation thereof with said shaft,

said centr ugal mechanism being adapted to raise said feeler memoer froma normal low position to a raised position during rotation of saidshaft,

a housing enclosing said mold and i eluding a wall portion spaced fromsaid tray to define an opening between said housing and said tray of asize sulficient to permit ice pieces discharged from said mold to dropinto said receptacle, the remaining portions of said housing beingarranged to confine released ice pieces and direct them to said opening,

water supply means including a solenoid valve,

a thermal switch movable to a cold position in response to a freezing ter perature of said ice mold and a warm position in response to anelevated temperature of said mold,

a mold operated switch movable to a first position when said mold isfilled and a second position when said mold is empty,

a normally closed ice level switch adapted to be opened when said feelermember is in its raised position,

a solenoid valve control circuit comprising said mold operated switch inits first position, said ice level switch and said thermal switch in itswarm position for opening said Valve when said mold is empty and at anelevated temperature,

a motor circuit including said mold operated switch in its secondposition and said thermal switch in its cold position for energizingsaid motor when said mold is filled and at a freezing temperature.

3. An automatic ice maker comprising;

a horizontally disposed ice mold from. which ice pieces formed thereinare centrifugally discharged upon rotation of said mold about a verticalaxis,

a receptacle for receiving ice pieces discharged from said mold,

drive means for rotating said mold,

ice level sensing means including a member movable between a normalposition extending into said receptacle and an elevated position andadapted to stop operation of said ice maker when the accumulation of icein said receptacle maintains said member in an elevated position,

and centrifugal means driven by said drive means for raising said memberduring rotation of said ice mold.

References Cited in the file of this patent UNITED STATES PATENTS

3. AN AUTOMATIC ICE MAKER COMPRISING; A HORIZONTALLY DISPOSED ICE MOLDFROM WHICH ICE PIECED FORMED THEREIN ARE CENTRIFUGALLY DISCHARGED UPONROTATION OF SAID MOLD ABOUT A VERTICAL AXIS, A RECEPTACLE FOR RECEIVINGICE PIECES DISCHARGED FROM SAID MOLD, DRIVE MEANS FOR ROTATING SAIDMOLD, ICE LEVEL SENSING MEANS INCLUDING A MEMBER MOVABLE BETWEEN ANORMAL POSITION EXTENDING INTO SAID RECEPTACLE AND AN ELEVATED POSITIONAND ADAPTED TO STOP OPERATION OF SAID ICE MAKER WHEN THE ACCUMULATION OFICE IN SAID RECEPTACLE MAINTAINS SAID MEMBER IN AN ELEVATED POSITION,AND CENTRIFUGAL MEANS DRIVEN BY SAID DRIVE MEANS FOR RAISING SAID MEMBERDURING ROTATION OF SAID ICE MOLD.